XXL cat litter box top lid

Our otherwise very good cat litter box came with an extra big entry hole at the top. However, our cat does not use it and we prefer to get less odour out of the box, so I designed a snap-in Lid for the hole. The lid has an outer and an inner part, because I am planning to add an air filter insert with charcoal pad for further odour reduction in the near future.

I printed the outer part with natural transparent PLA, so that light still gets into the box.